Multiplying by powers of ten is a quick and easy strategy to use and remember. If you are multiplying by 10, 100, 1 000 it is easy because you simply count the amount of zeros after the one, and tack on the same amount at the end of the other factor being multiplied. This can also be thought of as moving the decimal to the right the amount of places as there are zeros.
When the number is not 10, 100, 1000 etc, but is a number that does not begin with 1 you can use the same strategy with a small variation.
Multiplying by powers of ten is a quick and easy strategy to use and remember. If you are multiplying by 10, 100, 1 000 it is easy because you simply count the amount of zeros after the one, and tack on the same amount at the end of the other factor being multiplied. This can also be thought of as moving the decimal to the right the amount of places as there are zeros.
When the number is not 10, 100, 1000 etc, but is a number that does not begin with 1 you can use the same strategy with a small variation.